Proof - Sum of Measures of Angles in a Triangle are 180
Proof that the sum of the measures of the angles in a triangle are 180
S
Salman Khan
All Lessons in Geometry: Angles
1 Angle Basics
2 Introduction to angles (old)
3 Measuring Angles in Degrees
4 Using a Protractor
5 Measuring Angles
6 Angle-a-trons
7 Acute Right and Obtuse Angles
8 Acute Obtuse and Right Angles
9 Complementary and Supplementary Angles
10 Identifying Complementary and Supplementary Angles
11 Angles (part 2)
12 Proof - Sum of Measures of Angles in a Triangle are 180
13 Triangle Angle Example 1
14 Angles at the intersection of two lines
15 Proof-Vertical Angles are Equal
16 Angles (part 3)
17 Angles formed between transversals and parallel lines
18 Proof - Corresponding Angle Equivalence Implies Parallel Lines
19 Angles of parallel lines
20 Angles of parallel lines 2
21 Triangle Angle Example 2
22 Triangle Angle Example 3
23 Finding more angles
24 The Angle Game
25 Angle Game (part 2)
26 More on why SSA is not a postulate
27 Angles Formed by Parallel Lines and Transversals
28 Point Line Distance and Angle Bisectors
29 Two column proof showing segments are perpendicular
30 Angle Bisector Theorem Examples
31 Angle Bisector Theorem Proof
32 Inscribed and Central Angles
33 Perpendicular Radius Bisects Chord
34 Inradius Perimeter and Area
35 2003 AIME II Problem 7